Method and apparatus for forming Wi-Fi P2P group using Wi-Fi direct

ABSTRACT

Provided is a method for forming a Wi-Fi Peer-to-Peer (P2P) group using Wi-Fi Direct. The method includes acquiring device information of other P2P device corresponding to a connection target by P2P devices that will form a Wi-Fi P2P group; checking a type of the other P2P devices based on the acquired device information; adjusting an intent value of a P2P device depending on the checked type of the other P2P devices; and forming a Wi-Fi P2P group based on the adjusted intent values of the P2P devices.

CLAIM OF PRIORITY

This application claims, under 35 U.S.C. §119(a), priority to and thebenefit of the earlier filing date of, that patent application filed inthe Korean Intellectual Property Office on Aug. 8, 2011 and assignedSerial No. 10-2011-0078641, the entire disclosure of which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to wireless communications, andmore particularly, to a method and apparatus for forming a Wi-Fi P2Pgroup using Wi-Fi Direct.

2. Description of the Related Art

Mobile terminals, which have evolved into smart phones, provide avariety of useful features to users through applications, are downloadedover wireless networks that expand the operational functionality of thebasic mobile terminal. Among various features provided by mobileterminals, is a technology, referred to as Wi-Fi Direct that has beenproposed by the Wi-Fi Alliance.

Wi-Fi Direct, a new communication method proposed by the Wi-Fi Allianceprovides a feature in which devices supporting Wi-Fi Direct may shareinformation by communicating with each other without hotspots, routersand/or Access Points (APs). Common electronic devices having undergonecertification of Wi-Fi Direct, such as mobile terminals, printers,monitors, TVs, and game consoles, may perform wireless communicationwith each other using the Wi-Fi Direct technology.

Although Wi-Fi Direct is partially similar to Bluetooth in terms ofinter-device wireless communication capability, Wi-Fi Direct isadvantageous over Bluetooth in terms of the coverage and data rate. So,the Wi-Fi Direct feature may replace Bluetooth as the standardinter-device wireless communication technology. For example, whileBluetooth 4.0, the latest Bluetooth standard, supports coverage of amaximum of 100 m and a data rate of a maximum of 24 Mbps, Wi-Fi Directsupports coverage of a maximum of 200 m and a data rate of a maximum of300 Mbps. Therefore, Wi-Fi Direct has the advantage over Bluetooth inmany aspects.

Wi-Fi Direct, also called Wi-Fi P2P, supports a feature of forming aWi-Fi P2P network by forming a Peer-to-Peer group (P2P group) amongdevices. The P2P group is then referred to as a Wi-Fi P2P group andincludes a Group Owner (GO) and Group Clients (GCs).

A Group Owner, playing a role similar to the conventional wirelessrouter, plays a central role in the Wi-Fi P2P group, and allowsconnection of other devices (e.g., GCs) or adjusts start and end of theP2P group.

A Group Owner may be seen as an AP from the viewpoint of Group Clients.Group Clients, which are the remaining devices, except for GO in the P2Pgroup, operate as clients by being connected to the P2P group, and areprovided with a communication feature with the Group Owner and otherGroup Clients in the P2P group.

In Wi-Fi Direct, intent values of respective devices are compared inorder to form a Wi-Fi P2P group.

A device with the highest intent value becomes the Group Owner, and theother devices become Group Clients. Compared to Group Clients, the GroupOwner consumes more power because it controls the overall operation ofthe Wi-Fi P2P group. Therefore, if a mobile terminal powered by abattery (hereinafter referred to as a “battery-powered mobile terminal”)operates as Group Owner in the Wi-Fi P2P group, it is highly likely toreduce a running time (or driving time) of the mobile terminal due tothe rapid battery consumption.

However, when forming a Wi-Fi P2P group, the current Wi-Fi Directdetermines Group Owner by simply comparing intent values without anyother criteria, so the battery-powered mobile terminal is likely to bedetermined as Group Owner. For example, assuming that a battery-poweredmobile terminal and TV powered by a constant power source, such as wallpower (e.g., always-powered TV), form a Wi-Fi P2P group, the mobileterminal may be determined as a Group Owner, even though it would bedesirable to have the TV be the Group Owner when the battery replacementissue is considered.

Therefore, there is a need for a method and apparatus capable ofcomplementing the current Wi-Fi Direct feature of selecting Group Ownersby considering additional criteria for determining a Group Owner in aP2P network.

SUMMARY OF THE INVENTION

An aspect of exemplary embodiments of the present invention is toprovide a method and apparatus capable of forming a Wi-Fi P2P group soas to secure a maximum possible running time of a mobile terminal.

In accordance with one aspect of the present invention, there isprovided a method for forming a Wi-Fi Peer-to-Peer (P2P) group usingWi-Fi Direct. The method includes acquiring device information of P2Pdevices that will form a Wi-Fi P2P group; checking a type of each of theP2P devices based on the acquired device information; adjusting intentvalues of each of the P2P devices based on the checked type of other P2Pdevices; and forming a Wi-Fi P2P group based on the adjusted intentvalues of the P2P devices.

In accordance with another aspect of the present invention, there isprovided a method for forming a Wi-Fi Peer-to-Peer (P2P) group usingWi-Fi Direct. The method includes acquiring device information of P2Pdevices that will form a Wi-Fi P2P group; checking a possible runningtime of the P2P devices based on the acquired device information;adjusting intent values of the P2P devices depending on the checkedpossible running time of the P2P devices; and forming a Wi-Fi P2P groupbased on the adjusted intent values of the P2P devices.

In accordance with further another aspect of the present invention,there is provided an apparatus for forming a Wi-Fi Peer-to-Peer (P2P)group using Wi-Fi Direct. The apparatus includes a Wi-Fi module forproviding a short-range wireless communication function based on an IEEE802.11 standard; and a controller for acquiring device information ofanother P2P device corresponding to a connection target to form a Wi-FiP2P group by means of the Wi-Fi module, checking a type of other P2Pdevice based on the acquired device information, adjusting an intentvalue of a P2P device associated with the apparatus based on the checkedtype of the other P2P device, and forming a Wi-Fi P2P group with theother P2P devices based on the adjusted intent value.

In accordance with yet another aspect of the present invention, there isprovided an apparatus for forming a Wi-Fi Peer-to-Peer (P2P) group usingWi-Fi Direct. The apparatus includes a Wi-Fi module for providing ashort-range wireless communication function based on an IEEE 802.11standard; and a controller for acquiring device information of anotherP2P device corresponding to a connection target to form a Wi-Fi P2Pgroup by means of the Wi-Fi module, checking a possible running time ofthe other P2P device based on the acquired device information, adjustingan intent value of a P2P device associated with the apparatus dependingon the checked possible running time of the other P2P device, andforming a Wi-Fi P2P group with the other P2P device based on theadjusted intent value.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1A illustrates a Wi-Fi P2P group formed based on a Wi-Fi Directtechnology;

FIG. 1B is a block diagram of a mobile terminal according to anembodiment of the present invention;

FIG. 2 schematically illustrates a process of forming a Wi-Fi P2P groupby devices having undergone Wi-Fi Direct certification;

FIG. 3 illustrates a process of forming a Wi-Fi P2P group by adjustingintent values depending on types of devices according to an embodimentof the present invention;

FIG. 4 illustrates a first exemplary process of forming a Wi-Fi P2Pgroup by adjusting intent values depending on types of devices accordingto an embodiment of the present invention;

FIG. 5 illustrates a second exemplary process of forming a Wi-Fi P2Pgroup by adjusting intent values depending on types of devices accordingto an embodiment of the present invention;

FIG. 6 illustrates a process of forming a Wi-Fi P2P group by adjustingintent values depending on battery information according to anotherembodiment of the present invention; and

FIG. 7 illustrates a process of forming a Wi-Fi P2P group by adjustingintent values depending on battery information according to stillanother embodiment of the present invention.

Throughout the drawings, the same drawing reference numerals will beunderstood to refer to the same elements, features and structures.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the present invention will now be described indetail with reference to the accompanying drawings. In the followingdescription, specific details such as detailed configuration andcomponents are merely provided to assist the overall understanding ofexemplary embodiments of the present invention. Therefore, it should beapparent to those skilled in the art that various changes andmodifications of the embodiments described herein can be made withoutdeparting from the scope and spirit of the invention. In addition,descriptions of well-known functions and constructions are omitted forclarity and conciseness.

Among the terms set forth herein, a mobile or portable terminal orterminal refers to any kind of device capable of processing data that istransmitted or received to or from any external entity. The terminal maydisplay icons or menus on a screen to which stored data and variousexecutable functions are assigned or mapped. The terminal may representa computer, a notebook, a tablet PC, a mobile device, and the like.

FIG. 1A illustrates an exemplary Wi-Fi P2P group formed based on Wi-FiDirect technology.

Referring to FIG. 1A, P2P device 1 represents a mobile terminal, P2Pdevice 2 represents a TV, and a P2P device 3 represents a printer.Devices that may be included in a Wi-Fi P2P group are those devicesincluding a communication module complying with at least the IEEE802.11g standard (e.g., 802.11g and/or 802.11n) for Wireless Local AreaNetwork (WLAN), and satisfy certification criteria specified by theWi-Fi Alliance.

In an embodiment of the present invention, devices capable ofconstituting a Wi-Fi P2P group may be divided into devices powered by abattery (hereinafter referred to as ‘battery-powered devices’) anddevices powered by plug power or outlet power (hereinafter referred toas ‘always-powered devices’).

FIG. 1B is a block diagram of a mobile terminal according to anembodiment of the present invention, in which the mobile terminal isconsidered a battery-powered device.

A mobile terminal, to which an embodiment of the present invention isapplicable, may include mobile electronic devices that a user may easilycarry with him or her. For example, a mobile terminals may be videophones, cell phones, smart phones, International MobileTelecommunication 2000 (IMT-2000) terminals, Wideband Code DivisionMultiple Access (WCDMA) terminals, Universal Mobile TelecommunicationService (UMTS) terminals, Personal Digital Assistants (PDAs), PortableMultimedia Players (PMPs), Digital Multimedia Broadcasting (DMB)terminals, E-Books, portable computers (e.g., notebook computers, tabletcomputers, etc.), digital cameras, and portable gaming devices. A mobileterminal according to an embodiment of the present invention will bedescribed below with reference to FIG. 1B.

FIG. 1B illustrates an exemplary configuration of a mobile terminal inaccordance with the principles of the invention.

In this illustrated example, a wireless transceiver 23 includes a RadioFrequency (RF) unit (not shown) and a modulator/demodulator (modem) (notshown). The RF unit includes an RF transmitter for up-converting afrequency of transmission signals and amplifying the up-convertedtransmission signals, and an RF receiver for low-noise-amplifyingreceived signals and down-converting a frequency of the amplifiedsignals. The modem includes a transmitter for coding and modulatingtransmission signals, and a receiver for demodulating and decodingsignals received from the RF unit.

An audio processor 25 may include a coder/decoder (codec) (not shown).In addition, the codec may include both a data codec and an audio codec.The data codec processes data signals such as packet data, and the audiocodec processes audio signals such as voice and multimedia files. Theaudio processor 25 converts digital audio signals received from themodem into analog audio signals by means of the audio codec, and playsthe analog audio signals using a speaker (not shown). The audioprocessor 25 converts analog audio signals picked up by a microphone(not shown) into digital audio signals by means of the audio codec, andtransfers the digital audio signals to the modem. In an alternativeaspect, the codec may be included in a controller 10. In this casesignals received by the audio processor 25 are transferred to thecontroller for processing.

A key input unit 27 may include alphanumeric keys needed to inputnumeric and text information and function keys needed to set variousfunctions, or may include a touch pad. When a display 50 has acapacitive or resistive touch screen, the key input unit 27 may includea minimum number of predetermined keys, and the display 50 may partiallyreplace the key input function of the key input unit 27.

A memory 30 may include a program memory (not shown) and a data memory(not shown). The program memory stores programs for controlling theoverall operation of the mobile terminal. The data memory may storeinformation collected during the operation of the mobile terminal. Thememory 30 may further represent external memories such as Compact Flash(CF), Secure Digital (SD), Micro Secure Digital (Micro-SD), Mini SecureDigital (Mini-SD), Extreme Digital (xD), and memory stick. The memory 30may also include disks such as Hard Disk Drive (HDD) and Solid StateDisk (SSD).

A Wi-Fi module 40 provides a short-range wireless communication functionbased on the IEEE 802.11 standard. Using the Wi-Fi module 40, a user ofthe mobile terminal may form (or create) a Wi-Fi P2P group and enjoy adata exchange feature among Wi-Fi direct compliant devices.

The display 50 may include a Liquid Crystal Display (LCD) or an OrganicLight Emitting Diode (OLED), which is classified into Passive MatrixOLED (PMOLED) and Active Matrix OLED (AMOLED), respectively, and outputvarious display information generated by the mobile terminal When thedisplay 50 includes a capacitive or resistive touch screen, the display50 may operate as an input unit for controlling the mobile terminal.This touch screen capability may operate with the key input unit 27 orreplace the key input unit 27. Touch screen technology is well-known inthe art and need not be discussed in detail herein.

The controller 10 controls the overall operation of the mobile terminal,and may switch and control an operation of the mobile terminal dependingon user inputs received through the key input unit 27 or the display 50.In accordance with an embodiment of the present invention, thecontroller 10 may check a possible running time of the mobile terminalby checking the remaining amount of a battery (not shown). Battery levelmonitoring is a well-known method for determining a remaining life in abattery. Battery level monitoring is well-known in the art and need notbe discussed in detail herein.

The controller 10 acquires device information of other P2P devicescorresponding to a connection target to form a Wi-Fi P2P group by meansof the Wi-Fi module 40, checks a type of the other P2P devices based onthe acquired device information, adjusts an intent value of the P2Pdevice in which the controller is incorporated depending on the checkedtype of the other devices, and forms a Wi-Fi P2P group with the otherdevices based on the adjusted intent value.

Also, the controller 10 acquires device information of the other devicescorresponding to a connection target to form a Wi-Fi P2P group by meansof the Wi-Fi module 40, checks a possible running time of the otherdevices based on the acquired device information, adjusts an intentvalue of the P2P device in which the controller is incorporateddepending on the possible running time of the other devices, and forms aWi-Fi P2P group with the other devices based on the adjusted intentvalue.

As previously described, an always-powered device refers to a devicesuch as TV, printer, monitor, refrigerator, washer, and game console(e.g., Xbox) capable of forming a Wi-Fi P2P group with a mobile terminalthrough wireless communication. For example, if a mobile terminal is acamera and has formed a Wi-Fi P2P group with a printer, the mobileterminal may transmit captured images directly to the printer to havethe printer print out the transferred pictures.

FIG. 2 schematically illustrates a process of forming a Wi-Fi P2P groupby devices having undergone Wi-Fi Direct certification. Prior to adescription of an embodiment of the present invention for adjustingintent values depending on types of devices constituting a Wi-Fi P2Pgroup, a process of forming a Wi-Fi P2P group will be described belowwith reference to FIG. 2.

A process of forming a Wi-Fi P2P group may be achieved in three steps:device discovery 214, service discovery 216, and group creation 218.

Device Discovery

Connecting devices supporting Wi-Fi based on the Wi-Fi Direct feature iscalled creating (or forming) a Wi-Fi P2P group, and a device discoveryprocess 214 is a procedure needed to allow Wi-Fi devices (e.g., P2Pdevice 1, 210 and P2P device 2, 212) to recognize and connect with eachother, in order to form a Wi-Fi P2P group.

A Wi-Fi P2P device (e.g., P2P device 1, 210), which has entered a menuin which it desires to use the Wi-Fi Direct feature or has entered adevice discovery mode at a running request for an application, discoverssurrounding Wi-Fi P2P devices by repeating the functions of channelScan, Listen and Search specified by an IEEE 802.11 standard atintervals of a predetermined time. The basic operation of the devicesearch procedure performed in the process of forming a Wi-Fi P2P groupis performed by exchanging Probe Request and Probe Response messages ofan IEEE 802.11 MAC protocol. Probe Request includes information such asP2P IE, WSC IE and Supp Reg IE, and Probe Response includes P2P IE, WSCIE, RSN IE and Supp Reg IE. An embodiment of the present invention foradjusting intent values depending on types of devices constituting aWi-Fi P2P group may be realized based on WSC-IE information, and a fieldof WSC-IE includes information such as DEVICE PASSWORD ID, MANUFACTURER,MODEL NAME, MODEL NUMBER, SERIAL NUMBER, and DEVICE NAME. An embodimentof the present invention based thereon will be described later on withreference to FIGS. 3 and 5.

Service Discovery

Service discovery 216 may be optionally performed in the above-describeddevice discovery process and a group creation process 218 describedbelow. The service discovery process is performed to provide a featurein which each P2P device checks its supportable service protocol andservices and exchanges information about the services it can provide.

Assuming that a P2P device 1, 210 is a camera and a P2P device 2, 212 isa printer, if a user of the P2P device 1, 210 wants to output a photo,the P2P device 1, 210 may determine whether a photo output feature ofthe P2P device 2, 212 is available through the service search, becausethe P2P device 1, 210 needs to determine whether the P2P device 2, 212supports the photo output feature.

Assuming that file sharing between the P2P device 1, 210 and the P2Pdevice 2, 212 is requested through forming of a Wi-Fi P2P group, filesharing between the two devices may not be achieved if the P2P device 1,210 uses file sharing based on Universal Plug and Play (UPNP) but theP2P device 2, 212 uses file sharing based on Web Service (WS).Therefore, the service discovery process is not essential to create aWi-Fi P2P group, but corresponds to a necessary process.

Group Creation

A Wi-Fi P2P group requires a group creation process 218 for creating agroup, further includes determining a device that will play a centralrole (or Group Owner) in the Wi-Fi P2P group.

In Wi-Fi Direct, P2P devices (e.g., P2P device 1, 210 and P2P device 2,212) perform Provision Discovery to form or create a Wi-Fi P2P group,and the Provision Discovery is one of the important features defined inthe specification of Wi-Fi Direct.

P2P devices in Wi-Fi Direct basically operate based on Wi-Fi SimpleConfiguration (WSC), i.e., operate based on Wi-Fi Protected Setup (WPS).While WSC support of a connection device was optional in the existingWi-Fi standard, WSC support is mandatory in Wi-Fi Direct. WSC, a featureprovided for more convenient wireless connections, may be classified asa Push Button Configuration (PBC) scheme in which a button should bepushed and a PIN scheme in which a pin number should be input. For boththe PBC scheme and the PIN scheme, their setting should be completedwithin 120 seconds (which is inconveniently short). For example, in thePBC scheme, a WSC Registration Protocol starts and a Service SetIdentify (SSID) and credential necessary for connection are exchanged,only when a WPS button is input on another device within 120 secondsafter one device requested wireless connection based on the PBC scheme.

The newly defined standard in Wi-Fi Direct to relieve theseinconveniences of the conventional WSC is a Provision Discovery scheme,in which when a first Wi-Fi P2P device (e.g., P2P device 1, 210)attempts connection based on the conventional WSC (PBC scheme or PINscheme) after discovering another Wi-Fi P2P device (e.g., P2P device 2,212), the first Wi-Fi P2P device informs the other device's user of theconnection attempt by sending a WSC Configuration Method message.

The WSC Configuration Method message includes types: PBC, PIN fromDisplay, and PIN from Keypad. PBC allows the other device's user toreceive a button, and a PIN from Display and a PIN from Keypad mayinform the other device's user of the Wi-Fi P2P connection attempt bydisplaying a pin number on the other device or by an event where a pinnumber is received.

When the Provision Discovery is completed the users of the P2P device 1,210 and the P2P device 2, 212 accept the Wi-Fi P2P connection, and thena Group Owner Negotiation process is performed between the Wi-Fi P2Pdevices.

The Group Owner Negotiation process is performed by an exchange of a GONegotiation Request, a GO Negotiation Response and GO NegotiationConfirm frames, wherein the GO Negotiation Request and GO NegotiationResponse include P2P IE information and WSC IE information.

A P2P IE information field includes information such as P2P Capability,P2P Device Info, Group Owner Intent, Configuration Timeout, ListenChannel, Extended Listen Timing, Intended P2P Interface Address, ChannelList and Operating Channel attributes, and the WSC-IE information fieldincludes information such as DEVICE PASSWORD ID, MANUFACTURER, MODELNAME, MODEL NUMBER, SERIAL NUMBER, and DEVICE NAME.

For the P2P device 1, 210 and the P2P device 2, 212 their respectiveGroup Owner Intent values, which is preset randomly, included in P2P IEinformation are compared, and a device with a larger intent value isdetermined as the Group Owner, while a device with a smaller intentvalue is determined as a Group Client.

The Group Owner Negotiation process is completed when one of the devicesis determined to be a Group Owner and the other is determined to be theGroup Client. In the exemplary case shown herein P2P device 1, 210 isdeemed to be the Group Owner, while P2P device 2, 212 is deemed theGroup Client. If Provisioning for exchanging Credentials is completedand the device set as Group Owner operates as a WSC registrar and thedevice set as Group Client operates as a WSC Enrollee, a group settingprocess for forming a Wi-Fi P2P group is completed.

If the group forming process is completed, the Group Owner moves to anoperating channel and begins its role as the Group Owner. The GroupClient accesses the Group Owner with the credentials it checked throughProvisioning. Finally, the two devices are connected to the Wi-Fi P2Pgroup.

The process of forming a Wi-Fi P2P group by devices having undergoneWi-Fi Direct certification has been schematically described so far.Based thereon, a process of forming a Wi-Fi P2P group by adjustingintent values depending on types of devices will be described.

FIG. 3 illustrates a process of forming a Wi-Fi P2P group by adjustingintent values depending on types of devices according to an embodimentof the present invention. FIGS. 4 and 5 illustrate first and secondexemplary processes of forming a Wi-Fi P2P group by adjusting intentvalues depending on types of devices according to other embodiment ofthe present invention.

In describing an embodiment of the present invention in conjunction withFIG. 3, it is assumed that as shown in FIG. 5, a P2P device 1, 210 inFIG. 3 is a mobile terminal powered by a battery and a P2P device 2, 212is a device (e.g., TV) powered by constant power source (e.g., wallpower, such as outlet power). Although a greater number of devices inaddition to the two devices (the P2P device 1 and the P2P device 2) mayparticipate in creation of a Wi-Fi P2P group, it is assumed that two P2Pdevices participate in creation of a Wi-Fi P2P group, for conveniencepurpose only. An intent value of the other party's device may be checkedas it is included in a field (e.g., Group Owner Intent) of P2P IEdescribed in conjunction with FIG. 2.

In steps S301 and S302, the P2P device 1, 210 and the P2P device 2, 212each acquires device information of the other device and determineswhether the other device is a battery-powered device or analways-powered device.

The Probe Request and Probe Response messages exchanged in the devicediscovery mode described in conjunction with FIG. 2 include WSC-IEinformation, and a field of WSC-IE includes device information.

Therefore, the P2P device 1, 210 may determine that the other device(P2P device 2, 212) is an always-powered device, based on theinformation included in the field of WSC-IE, such as DEVICE PASSWORD ID,MANUFACTURER, MODEL NAME, MODEL NUMBER, SERIAL NUMBER and DEVICE NAME,and the P2P device 2, 212 may determine that the other device (P2Pdevice 1, 210) is a battery-powered device.

For example, if it is checked that Model Name of the P2P device 1, 210is Galaxy S™ and Device Name thereof is portable device, the P2P device2, 212 may determine that the P2P device 1, 210 is a mobile terminal.Also, if it is checked that Model Name of P2P device 2, 212 is Pavv™ andDevice Name thereof is TV, the P2P device 1, 212 may determine that theP2P device 2, 212 is a device powered by a constant power source.

In step S303, the P2P device 1, 210 and the P2P device 2, 212 eachadjusts its own intent value depending on a type of the other device.

For example, if device 1, 210 determines that the P2P device 2, 212 isan always-powered device, the P2P device 1, 210 adjusts its intent valueto be lower than an intent value of the P2P device 2, 212. Similarly, ifdevice 2, 212 determines that the P2P device 1, 210 is a battery-powereddevice, the P2P device 2, 210 adjusts its intent value to be higher thanan intent value of the P2P device 1, 210.

In step S304 the WI-FI P2P group is then created with device 1, 210 anddevice 2, 212, wherein the device with the higher intent value isselected as the Group Owner.

Referring to FIG. 4, adjusting intent values will be described in moredetail. In Wi-Fi Direct, intent values may have values of 0 to 15. Inadjusting intent values depending on types of devices, an embodiment ofthe present invention limits settable intent values according to typesof devices.

For example, in the conventional Wi-Fi Direct, both the battery-powereddevice and the always-powered device may have intent values of 0 to 15.Conventionally, therefore, the mobile terminal may operate as GO in theWi-Fi P2P group when it has an intent value that is higher than theintent value of the always-powered device.

Taking this into account, in one embodiment of the present invention amaximum intent value of a mobile terminal is set to 7, and a minimumintent value of an always-powered device is set to 8. Therefore, in stepS303, the P2P device 1, 210 may adjust its intent value to any one ofthe intent values in the range of 0 to 7 (i.e., a first range, 410), ifit is determined that the P2P device 1, 210 is a mobile terminal, andthe P2P device 2, 212 is an always-powered device. Similarly, the P2Pdevice 2, 212 may adjust its intent value to an intent value in therange of 8 to 15 (i.e., a second range, 420), if it is determined thatthe P2P device 2, 212 is an always-powered device and the P2P device 1,210 is a battery powered device.

For example, when P2P device 1, 210 is a battery-powered device, it mayreduce its current intent value by some number of units (e.g., two)until the intent value is within the range of 0-7. Similarly, the P2Pdevice 2, 212 may increase its intent value by increasing its currentintent value by a number of units (e.g., 3 units) until the intent valueis within the range of 8-15.

In step S304, the P2P device 1 and the P2P device 2 each performs theremaining operation related to Wi-Fi P2P group creation based on theadjusted intent values, as previously described. If the Group OwnerNegotiation process described in conjunction with FIG. 2 is performedafter the intent value of the P2P device 1, 210 is adjusted to besmaller than the intent value of the P2P device 2, 212, the P2P device 1is set as GC and the P2P device 2 is set as the GO in creating a Wi-FiP2P group.

In this manner, an embodiment of the present invention may prevent thebattery-powered P2P device 1, 210 from being set as GO, thus extending arunning time of the P2P device 1, 210 compared to when the P2P device 1,210 is set as the GO.

For example, when a Wi-Fi P2P group is formed or created between a P2Pdevice 1 (e.g., mobile terminal) and a P2P device 2 (e.g., TV powered bywall power) as shown in FIG. 5, the always-powered TV operates as theGroup Owner based on the adjusted intent values.

Thus, if a battery of the P2P device 1, 210 is selected as the GO andbecomes exhausted with the Wi-Fi P2P group created between the P2Pdevice 1, 210 and the P2P device 2, 212, the Wi-Fi P2P group can nolonger be maintained. Hence, in accordance with an embodiment of thepresent invention described in conjunction with FIG. 3 a running time ofthe Wi-Fi P2P group may be extended as the Group Owner is alwaysselected as the device that is provided with a constant power supply.

FIG. 6 illustrates a process of forming a Wi-Fi P2P group by adjustingintent values depending on battery information according to anotherembodiment of the present invention. FIG. 7 illustrates a process offorming a Wi-Fi P2P group by adjusting intent values depending onbattery information according to still another embodiment of the presentinvention.

Although an embodiment of the present invention described in conjunctionwith FIG. 3 is an embodiment in which the P2P device 2, 212 is set asthe GO because the P2P device 1, 210 is a mobile terminal and the P2Pdevice 2, 212 is an always-powered device, another embodiment of thepresent invention described in conjunction with FIG. 6 is an embodimentfor forming a Wi-Fi P2P group by adjusting intent values when the P2Pdevice 1, 210 and the P2P device 2, 212 are both mobile terminals.

In steps S601 and S602, P2P device 1, 210 and P2P device 2, 212, eachacquire device information of the other device, and determine that theother device is also a battery-powered mobile terminal.

As described in conjunction with FIGS. 2 and 3, in steps S601 and S602,the P2P device 1, 210 and the P2P device 2, 212 each may determine thatthe other device is a mobile terminal, based on WSC-IE informationincluded in a Probe Request or Probe Response message.

Thereafter, in steps S603 and S604, the P2P device 1, 210 and the P2Pdevice 2, 212 each compares battery information of the other device withits own battery information, and adjusts its intent value based on thecomparison results.

In another embodiment of the present invention, battery informationincludes information about the possible running time (or possibledriving time) of the mobile terminal based on the battery levelpresently in use, and the battery information may be construed as partof the device information described in conjunction with FIG. 3. Thebattery information may be inserted into an idle field of P2P IE orWSC-IE included in the Probe Request or Probe Response messagesdescribed in conjunction with FIG. 2. In other words, each of the P2Pdevices (i.e., P2P device 1 and P2P device 2) according to thisembodiment of the present invention described in conjunction with FIG. 6may transmit its battery information to the other device by insertingthe battery information into an idle field of P2P IE or WSC-IE whenexchanging Probe Request and Probe Response messages in the devicediscovery mode.

In an exemplary example, device 1, 210 determines P2P device 2, 212 is amobile terminal, the P2P device 1, 210 determines that its own possiblerunning time is greater than a possible running time of the P2P device2, through a comparison of battery information, and adjusts its intentvalue to be greater than an intent value of the P2P device 2.

Similarly, device 2, 212 determines that the P2P device 1, 210 is amobile terminal, the P2P device 2 determines that its own possiblerunning time is less than a possible running time of the P2P device 1,through a comparison of battery information, and adjusts its intentvalue to be less than an intent value of the P2P device 1, 210. Aspreviously described, the intent value is to be included in a field(e.g., Group Owner Intent) of P2P IE described in conjunction with FIG.2.

In one aspect of the invention, in this case described above, P2P device1,210 may increase its intent value by a known number of units until theintent value is in the range of 8-15, for example. Similarly, P2P device2, 212 may decrease its intent value by a second known number units unitthe intent value is in the range of 0-7, for example. As would beappreciated, the values of the known number of units, referred toherein, are only exemplary values used to describe a process forincreasing and decreasing intent values. However, it would be recognizedother methods for increasing and decreasing intent values may beemployed without altering the scope of the invention.

In step S605, the P2P device 1, 210 and the P2P device 2, 212 eachperforms the remaining operation related to Wi-Fi P2P group creationbased on the adjusted intent values.

If the Group Owner Negotiation process described in conjunction withFIG. 2 is performed after an intent value of the P2P device 1, 210 isadjusted to be greater than an intent value of the P2P device 2 throughsteps S601 to S604, the P2P device 1 is set as GO and the P2P device 2is set as GC, creating a Wi-Fi P2P group.

Referring to FIG. 7, as for the P2P device 1, 210 and the P2P device 2,212 (both are mobile terminals), the P2P device 1, 210 whose possiblerunning time is longer is set as the GO and the P2P device 2 whosepossible running time is shorter is set as the GC, creating a Wi-Fi P2Pgroup. Although, the example provided herein to illustrate the presentinvention describes P2P device 1, 210 as having a longer possible runtime, it would be appreciated that the intent value of P2P device 2, 212may be adjusted to be greater than P2P device 1, 210 when the possiblerunning time of P2P device 2, 212 is greater than that of P2P device 1,210.

In another embodiment of the present invention, when mobile terminalsconstitute a Wi-Fi Direct group (or Wi-Fi P2P group), a device with alonger possible running time of a battery is set as the GO, making itpossible to extent the possible running time of the Wi-Fi P2P group. Forexample, if the P2P device 2, 212 with a possible running time of 45minutes is set as the Group Owner, the possible running time of theWi-Fi P2P group may be about 45 minutes. However, if the P2P device 1,210 with a possible running time of 60 minutes is set as the GroupOwner, the possible running time of the Wi-Fi P2P group may be about 60minutes, extending the possible running time of the Wi-Fi P2P group by15 minutes.

As is apparent from the foregoing description, according to exemplaryembodiments of the present invention, when a battery-powered mobileterminal and an always-powered device form a Wi-Fi P2P group, thealways-powered device is set as the Group Owner, making it possible tosecure the maximum possible running time of the mobile terminal.

Similarly, when battery-powered mobile terminals form a Wi-Fi P2P group,a mobile terminal with a longer possible running time is set as theGroup Owner, making it possible to secure the maximum possible runningtime of the Wi-Fi P2P group.

The above-described methods according to the present invention can beimplemented in hardware, firmware or as software or computer code thatcan be stored in a recording medium such as a CD ROM, an RAM, a floppydisk, a hard disk, or a magneto-optical disk or computer code downloadedover a network originally stored on a remote recording medium or anon-transitory machine readable medium and to be stored on a localrecording medium, so that the methods described herein can be renderedin such software that is stored on the recording medium using a generalpurpose computer, or a special processor or in programmable or dedicatedhardware, such as an ASIC or FPGA. As would be understood in the art,the computer, the processor, microprocessor controller or theprogrammable hardware include memory components, e.g., RAM, ROM, Flash,etc. that may store or receive software or computer code that whenaccessed and executed by the computer, processor or hardware implementthe processing methods described herein. In addition, it would berecognized that when a general purpose computer accesses code forimplementing the processing shown herein, the execution of the codetransforms the general purpose computer into a special purpose computerfor executing the processing shown herein.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method performed by a first device for forminga Wi-Fi Peer-to-Peer (P2P) group with at least one second device usingWi-Fi Direct, the method comprising: receiving at least one deviceinformation of the at least one second device; adjusting an intentvalues of the first device based on a type of the at least one seconddevice corresponding to the received device information of the at leastone second device; and processing at least one operation related toformation of the Wi-Fi P2P group using the adjusted intent value.
 2. Themethod of claim 1, wherein the device information is included in atleast one of Peer to Peer Information-Element (P2P IE) and Wi-Fi SimpleConfiguration Information-Element (WSC-IE).
 3. The method of claim 1,further comprising checking a type of the at least one second device,which comprises: determining whether the at least one second device is abattery-powered mobile terminal or an always-powered device.
 4. Themethod of claim 3, wherein the adjusting an intent values of the firstdevice comprises: reducing the intent value of the first device if thefirst device is a battery-powered device and the at least one seconddevices is an always-powered device.
 5. The method of claim 3, whereinthe adjusting the intent value of the first device comprises: increasingthe intent value of the first device if the first device is analways-powered device and the at least one second device is abattery-powered device.
 6. The method of claim 1, wherein adjusting theintent of the first device comprises: reducing the intent value to fallwithin a first range if the first device is a battery powered device andthe at least one second device is determined to be an always-powereddevice, and increasing the intent value of the first device to fallwithin a second range higher than the first range if the first device isan always-powered device and the at least one second device isdetermined to be a battery-powered device.
 7. The method of claim 1,wherein forming the Wi-Fi P2P group comprises: forming the Wi-Fi P2Pgroup such that among devices of the group, a device with a greaterintent value operates as a group owner and a device with a smallerintent value is set as a group client.
 8. A method performed by a firstPeer-to-Peer (P2P) device for forming a Wi-Fi P2P group with at leastone second P2P device using Wi-Fi Direct, the method comprising:acquiring device information of the at least one second P2P device;checking a possible running time of the at least one second device basedon the acquired device information; adjusting an intent value of thefirst P2P device based on a comparison of the possible running time ofthe at least one second P2P device with a possible running time of thefirst P2P device; and forming the Wi-Fi P2P group using the adjustedintent value.
 9. The method of claim 8, wherein the device informationis included in at least one of a Peer to Peer Information-Element (P2PIE) and a Wi-Fi Simple Configuration Information-Element (WSC-IE), andincludes information about the P2P device's possible running time,including battery information of the P2P device.
 10. The method of claim9, wherein the first device and the at least one second device are eachmobile terminals and adjusting an intent values comprises: reducing theintent value of the first device when the possible running time of thefirst device is shorter than the possible running time of the at leastone second device.
 11. The method of claim 8, wherein the checking apossible running time of the at least one second P2P devices comprises:determining whether the at least one second P2P devices is abattery-powered mobile terminal.
 12. The method of claim 8, wherein thefirst P2P device and the at least one second P2P device are each mobileterminals, and adjusting an intent value comprises: increasing theintent value of the first P2P device when the possible running time ofthe first P2P device is longer than the possible running time of the atleast one second P2P device.
 13. The method of claim 8, wherein theforming a Wi-Fi P2P group comprises: selecting a P2P device with agreater intent value as a group owner and setting a P2P device with alower intent value as a group client.
 14. An apparatus for forming aWi-Fi Peer-to-Peer (P2P) group using Wi-Fi Direct, comprising: a Wi-Fimodule providing a short-range wireless communication function based onan IEEE 802.11 standard; and a controller: acquiring device informationof P2P devices to form the Wi-Fi P2P group by means of the Wi-Fi module,checking a type of each of the P2P devices based on the acquired deviceinformation, adjusting an intent value of a P2P device associated withthe apparatus depending on the checked type of each of the other P2Pdevices, and forming the Wi-Fi P2P group with the P2P device based onthe adjusted intent value.
 15. The apparatus of claim 14, wherein thedevice information is included in at least one of a Peer to PeerInformation-Element (P2P IE) and a Wi-Fi Simple ConfigurationInformation-Element (WSC-IE).
 16. The apparatus of claim 14, wherein thecontroller determines whether the P2P devices are battery-powered oralways-powered devices.
 17. The apparatus of claim 16, wherein thecontroller adjusts the intent value of the P2P device associated withthe apparatus to be less, if the P2P device is a battery-powered mobileterminal and at least one of the other P2P devices is an always-powereddevice.
 18. The apparatus of claim 16, wherein the controller adjuststhe intent value of the P2P device associated with the apparatus to begreater, if the P2P device associated with the apparatus is analways-powered device.
 19. The apparatus of claim 16, wherein adjustingthe intent value causes the intent value to be in one of: a first rangeand a second range.
 20. The apparatus of claim 14, wherein the Wi-Fi P2Pgroup is formed such that a P2P device with a greater intent valueoperates as a group owner and a P2P device with a less intent value isset as a group client.
 21. An apparatus for forming a Wi-Fi Peer-to-Peer(P2P) group using Wi-Fi Direct, comprising: a Wi-Fi module providing ashort-range wireless communication function based on an IEEE 802.11standard; and a controller: acquiring device information of other P2Pdevices corresponding to a connection target to form a Wi-Fi P2P groupby means of the Wi-Fi module, checking a possible running time of theother P2P devices based on the acquired device information, adjusting anintent value of a P2P device associated with the apparatus depending onthe checked possible running time of the other P2P devices, and forminga Wi-Fi P2P group with the other P2P devices based on the adjustedintent value.
 22. The apparatus of claim 21, wherein the deviceinformation is included in at least one of a Peer to PeerInformation-Element (P2P IE) and a Wi-Fi Simple ConfigurationInformation-Element (WSC-IE), and includes information about the P2Pdevice's possible running time, including battery information of the P2Pdevice.
 23. The apparatus of claim 22, wherein the controller further:compares a possible running time of the P2P device associated with theapparatus with a possible running time of the other P2P devices if theP2P device and the other P2P devices are mobile terminals; and adjuststhe intent value of the P2P device associated with the apparatus to begreater if the possible running time of the P2P device associated withthe apparatus is longer than the possible running time of the other P2Pdevices.
 24. The apparatus of claim 22, wherein the controller further:compares a possible running time of the P2P device associated with theapparatus with a possible running time of the other P2P devices if theP2P device and the other P2P devices are mobile terminals; and adjuststhe intent value of the P2P device associated with the apparatus to beless if the possible running time of the P2P device associated with theapparatus is shorter than the possible running time of the other P2Pdevice.
 25. The apparatus of claim 21, wherein the controller determineswhether the other P2P devices are battery-powered.
 26. The apparatus ofclaim 21, wherein the Wi-Fi P2P group is formed such that a P2P devicewith a greater intent value operates as a group owner and a P2P devicewith a less intent value is set as a group client.